(1) Field of the Invention
The present invention relates to a fluid spray head and to a machine for manufacturing such a head.
(2) Description of Related Art
Fluid dispenser heads are well known, in particular in the field of pharmacy. In order to dispense a fine spray, the head generally includes a spray profile disposed just upstream from the spray orifice. The characteristics of the spray, in particular the size distribution of the droplets and the reproducibility of such characteristics, are largely dependent on the shape of said spray profile. It turns out that in most fluid dispenser devices, in particular of medicines, the performance is not very consistent because of manufacturing tolerances during molding of the head. In particular, this is explained by the very small dimensions required in particular for the spray orifice, which implies using punches that are relatively fragile. In existing devices, the spray profile is molded inside the head by means of a core pin that is inserted into a head cavity, and that includes, on it front face, a profile that is complementary to the spray profile to be made in the end face of the expulsion channel formed inside the head. The punch used to make the spray orifice is generally provided on the end wall of the cavity for molding the head. Thus, during injection, which is never completely concentric, substantial stresses are exerted on said punch, which, because of its small dimensions, is displaced relative to the pin defining the profile. This causes the central axis of the spray orifice to be offset from the central axis of the spray chamber. Such offset can be substantial, and can in particular vary greatly from one head to another.
This prevents consistent spray characteristics from being obtained.